CD40LG and 22q11.2 deletion syndrome: Concerning the levels of immunoglobulins, a large study conducted by the European Society for Immunodeficiency and the US Immunodeficiency Network, involving 1023 patients diagnosed with a DiGeorge syndrome, revealed that only a small proportion of children older than 3 years had a decreased immunoglobulin levels (6.2% for IgG, 1.3% for IgA, and 23% for IgM),38 similarly to our study.